Electrochromic multi-layer devices with composite electrically conductive layers

Abstract

A multi-layer device comprising a first substrate and a first electrically conductive layer on a surface thereof, the first electrically conductive layer having a sheet resistance to the flow of electrical current through the first electrically conductive layer that varies as a function of position.

What is claimed is: 
     
       1. A multi-layer device comprising a first substrate and a first patterned electrically conductive layer on a surface of the first substrate, the first patterned electrically conductive layer being transmissive to electromagnetic radiation having a wavelength in the range of infrared to ultraviolet on a surface of the first substrate, the first patterned composite electrically conductive layer comprising a transparent electrically conductive material, the first patterned electrically conductive layer having an average sheet resistance wherein a ratio of the average sheet resistance in a first region of the first electrically conductive layer circumscribed by a first convex polygon to the average sheet resistance in a second region of the first conductive layer circumscribed by a second convex polygon is at least 2, the first and second regions circumscribed by the first and second convex polygons, respectively, each comprising at least 25% of the surface area of the first electrically conductive layer. 
     
     
       2. The multi-layer device of  claim 1  wherein the first electrically conductive layer has a spatially varying sheet resistance, R s , that varies as a function of position in the first electrically conductive layer, a contour map of the sheet resistance, R s , as a function of position within the first electrically conductive layer contains a set of isoresistance lines and a set of resistance gradient lines normal to the isoresistance lines, and the sheet resistance along a gradient line in the set generally increases, generally decreases, generally increases until it reaches a maximum and then generally decreases, or generally decreases until it reaches a minimum and then generally increases. 
     
     
       3. The multi-layer device of  claim 1  wherein the first substrate is transparent to electromagnetic radiation having a wavelength in the range of infrared to ultraviolet. 
     
     
       4. The multi-layer device of  claim 1 , the multi-layer device further comprising a first electrode layer on a surface of the first electrically conductive layer, the first electrically conductive layer being between the first electrode layer and the first substrate. 
     
     
       5. The multi-layer device of  claim 4  wherein the first electrode layer comprises an electrochromic material. 
     
     
       6. The multi-layer device of  claim 4 , the multi-layer device further comprising a second electrically conductive layer, the first electrode layer being transparent to electromagnetic radiation having a wavelength in the range of infrared to ultraviolet and located between the first and second electrically conductive layers, the second electrically conductive layer having a sheet resistance, R s , to the flow of electrical current through the second electrically conductive layer that varies as a function of position in the first electrically conductive layer wherein the ratio of the value of maximum sheet resistance, R max , to the value of minimum sheet resistance, R min , in the second electrically conductive layer is at least 2. 
     
     
       7. The multi-layer device of  claim 6  wherein the ratio of the average sheet resistance in a first region of the second electrically conductive layer circumscribed by a first convex polygon to the average sheet resistance in a second region of the second conductive layer circumscribed by a second convex polygon is at least 2, the first and second regions circumscribed by the first and second convex polygons, respectively, each comprising at least 25% of the surface area of the second electrically conductive layer. 
     
     
       8. The multi-layer device of  claim 6  wherein the second electrically conductive layer has a spatially varying sheet resistance, R s , that varies as a function of position in the second electrically conductive layer, a contour map of the sheet resistance, R s , as a function of position within the second electrically conductive layer contains a set of isoresistance lines and a set of resistance gradient lines normal to the isoresistance lines, and the sheet resistance along a gradient line in the set generally increases, generally decreases, generally increases until it reaches a maximum and then generally decreases, or generally decreases until it reaches a minimum and then generally increases. 
     
     
       9. The multi-layer device of  claim 6  wherein (a) the first electrically conductive layer comprises a region A 1  and a region B 1  wherein region A 1  and region B 1  each comprise at least 25% of the surface area of the first electrically conductive layer, are each circumscribed by a convex polygon and are mutually exclusive, (b) a projection of region A 1  onto the second electrically conductive layer defines a region A circumscribed by a convex polygon in the second electrically conductive layer comprising at least 25% of the surface area of the second electrically conductive, (c) a projection of region B 1  onto the second electrically conductive layer defines a region B circumscribed by a convex polygon in the second electrically conductive layer comprising at least 25% of the surface area of the second electrically conductive, (d) the first electrically conductive layer has an average sheet resistance in region A 1  corresponding to R A1   avg  and an average sheet resistance in region B 1  corresponding to R B1   avg  (e) the second electrically conductive layer has an average sheet resistance in region A corresponding to R A   avg  and an average sheet resistance in region B corresponding to R B   avg , (f) the ratio of R A1   avg  to R B1   avg  or the ratio of R B   avg  to R A   avg  is at least 1.5 and (g) the ratio of (R A1   avg /R A   avg ) to (R B1   avg /R B   avg ) is at least 1.5. 
     
     
       10. The multi-layer device of  claim 6 , the multi-layer device further comprising a second substrate, the second electrically conductive layer being between the second substrate and the first electrically conductive layer. 
     
     
       11. The multi-layer device of  claim 10  wherein the second substrate is transparent to electromagnetic radiation having a wavelength in the range of infrared to ultraviolet. 
     
     
       12. The multi-layer device of  claim 4 , the multi-layer device further comprising an ion conducting layer, the first electrode layer being between the ion conducting layer and the first electrically conductive layer, the ion conducting layer being a dielectric material having an ionic conductivity for carrier ions of at least 10 −7  Siemens/cm at 25° C. 
     
     
       13. The multi-layer device of  claim 12 , the multi-layer device further comprising a second electrode layer, the ion conducting layer being between the first and second electrode layers. 
     
     
       14. The multi-layer device of  claim 13  wherein the second electrode layer comprises an electrochromic material. 
     
     
       15. The multi-layer device of  claim 1  wherein the first substrate has an inner surface facing the first electrically conductive layer, the surface area of the inner surface of the first substrate being at least 0.1 meter 2 . 
     
     
       16. The multi-layer device of  claim 1  wherein the first electrically conductive layer comprises a first material and a second material, the first material being a transparent conductive oxide and the second material having a resistivity that is greater than the resistivity of the first material by a factor of at least 10 2 . 
     
     
       17. An electrochromic device comprising a first substrate, a first electrically conductive layer, a first electrode layer, a second electrically conductive layer and a second substrate, at least one of the first and second electrically conductive layers comprising a patterned electrically conductive layer, the first and second electrically conductive layers each having a sheet resistance, R s , to the flow of electrical current through the first and second electrically conductive layers that varies as a function of position in the first and second electrically conductive layers, respectively, wherein the ratio of the value of maximum sheet resistance, R max , to the value of minimum sheet resistance, R min , in the first electrically conductive layer is at least 2 and the ratio of the value of maximum sheet resistance, R max , to the value of minimum sheet resistance, R min , in the second electrically conductive layer is at least 2, the first substrate and the first electrically conductive layer being transmissive to electromagnetic radiation having a wavelength in the range of infrared to ultraviolet. 
     
     
       18. The electrochromic device of  claim 17 , further comprising first and second busbars respectively coupled to the first and second electrically conductive layers wherein (i) the first and second busbars are configured to receive a drive current I DRV  to enable a current driven mode for switching the electrochromic device to a target optical state with respect to a minimum optical state and a maximum optical state thereof; (ii) the electrochromic device comprises a total charge capacity having a total charge Q TOT ; (iii) the target optical state is attainable by charging the electrochromic device to a target charge Q TGT  via the drive current I DRV , the target charge Q TGT  comprises a percentage of the total charge Q TOT  corresponding to a percentage of the target optical state relative to the maximum optical state; and (iv) the target optical state is predictably attainable for substantially all of a total optically switchable area of the electrochromic device, and within a target time T TGT , by adjustment of the drive current I DRV  such that the product of the target time T TGT  and the drive current I DRV  substantially equals the target charge Q TGT . 
     
     
       19. The electrochromic device of  claim 18 , wherein when the electrocromic device is switched from an initial optical state to the target optical state, an opacity of the total optically switchable area is adjusted substantially uniformly for each locality thereof within the target time T TGT . 
     
     
       20. The electrochromic device of  claim 18 , wherein the optically switchable area of the electrochromic device is transitionable to the target optical state once the drive current I DRV  is adjusted to a constant current value corresponding to the target time T TGT . 
     
     
       21. The electrochromic device of  17  wherein (i) the ratio of the average sheet resistance in a first region of the first electrically conductive layer circumscribed by a first convex polygon to the average sheet resistance in a second region of the first electrically conductive layer circumscribed by a second convex polygon is at least 2, the first and second regions of the first electrically conductive layer each comprising at least 25% of the surface area of the first electrically conductive layer and (ii) the ratio of the average sheet resistance in a first region of the second electrically conductive layer circumscribed by a first convex polygon to the average sheet resistance in a second region of the second electrically conductive layer circumscribed by a second convex polygon is at least 2, the first and second regions of the second electrically conductive layer each comprising at least 25% of the surface area of the second electrically conductive layer. 
     
     
       22. The electrochromic device of  claim 17  wherein the first electrically conductive layer has a spatially varying sheet resistance, R s , that varies as a function of position in the first electrically conductive layer, a contour map of the sheet resistance, R s , as a function of position within the first electrically conductive layer contains a set of isoresistance lines and a set of resistance gradient lines normal to the isoresistance lines, and the sheet resistance along a gradient line in the set generally increases, generally decreases, generally increases until it reaches a maximum and then generally decreases, or generally decreases until it reaches a minimum and then generally increases. 
     
     
       23. The electrochromic device of  claim 22  wherein the second electrically conductive layer has a spatially varying sheet resistance, R s , that varies as a function of position in the second electrically conductive layer, a contour map of the sheet resistance, R s , as a function of position within the second electrically conductive layer contains a set of isoresistance lines and a set of resistance gradient lines normal to the isoresistance lines, and the sheet resistance along a gradient line in the set generally increases, generally decreases, generally increases until it reaches a maximum and then generally decreases, or generally decreases until it reaches a minimum and then generally increases. 
     
     
       24. The electrochromic device of  claim 22  wherein (i) the first electrically conductive layer has a spatially varying sheet resistance, R s , that varies as a function of position in the first electrically conductive layer, (ii) a contour map of the sheet resistance, R s , as a function of position within the first electrically conductive layer contains a set of isoresistance lines and a set of resistance gradient lines normal to the isoresistance lines, and (iii) a projection of a line segment having a length of at least 1 cm of one of the gradient lines onto the second electrically conductive layer defines a complementary line segment in the second electrically conductive layer wherein (a) the average value of the slope of the sheet resistance of the first electrically conductive layer over the gradient line segment, S 1   avg , is a positive or negative value, and (b) the average value of the slope of the sheet resistance of the second electrically conductive layer over the complementary line segment, S 2   avg , is zero or is opposite in sign to S 1   avg . 
     
     
       25. The electrochromic device of  claim 17  wherein the second substrate and the second electrically conductive layer are transparent to electromagnetic radiation having a wavelength in the range of infrared to ultraviolet. 
     
     
       26. The electrochromic device of  claim 17  wherein the electrochromic device comprises, in succession, the first substrate, the first electrically conductive layer, the first electrode layer, an ion conducting layer, a second electrode layer, the second electrically conductive layer and the second substrate. 
     
     
       27. The electrochromic device of  claim 17  wherein the first electrically conductive layer comprises a first material and a second material, the first material being a transparent conductive oxide and the second material having a resistivity that is greater than the resistivity of the first material by a factor of at least 10 2 . 
     
     
       28. A process for the preparation of a multi-layer device comprising forming a multi-layer layer structure comprising an electrochromic layer between and in electrical contact with a first and a second electrically conductive layer, at least one of the first and second electrically conductive layers comprising a patterned electrically conductive layer, the first and/or the second electrically conductive layer having a spatially varying sheet resistance, R s , to the flow of electrical current through the first and/or the second electrically conductive layer that varies as a function of position in the first and/or the second electrically conductive layer, respectively, wherein the ratio of the average sheet resistance in a first region of the first electrically conductive layer circumscribed by a first convex polygon to the average sheet resistance in a second region of the first electrically conductive layer circumscribed by a second convex polygon is at least 2, the first and second regions circumscribed by the first and second convex polygons, respectively, each comprising at least 25% of the surface area of the first electrically conductive layer. 
     
     
       29. The process of  claim 28  wherein the first electrically conductive layer has a spatially varying sheet resistance, R s , that varies as a function of position in the first electrically conductive layer, a contour map of the sheet resistance, R s , as a function of position within the first electrically conductive layer contains a set of isoresistance lines and a set of resistance gradient lines normal to the isoresistance lines, and the sheet resistance along a gradient line in the set generally increases, generally decreases, generally increases until it reaches a maximum and then generally decreases, or generally decreases until it reaches a minimum and then generally increases. 
     
     
       30. The process of  claim 28  wherein the first electrically conductive layer comprises a first material and a second material, the first material being a transparent conductive oxide and the second material having a resistivity that is greater than the resistivity of the first material by a factor of at least 10 2 .